Network Management Apparatus and Network Management Method

1. A network management apparatus, comprising: a first storage unit that stores therein communication groups included in the same subnet and information about communication devices belonging to the respective communication groups in association with each other, the information about communication devices including a model name of each communication device and an ID that identifies each communication device; a second storage unit that stores therein a port of each communication device for each of the communication devices connected to a relaying device as a connection destination port; and a controller that allows the relaying devices to perform communication between the connection destination ports on the basis of the first storage unit and the second storage unit to allow communication between the communication devices belonging to the same communication group, and to disallow communication between the communication devices not belonging to the same communication group, wherein when one or more of the communication devices is caused to participate in the communication group, the network management apparatus further comprises: a port searching unit that searches for the connection destination ports controlling communication between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate on the basis of the first storage unit and the second storage unit; and a relaying device control unit that controls the connection destination ports searched by the port searching unit to be active to allow communication only between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate when the model names of the communication devices caused to participate in the communication group can be acquired from the first storage unit.

2. The network management apparatus according to claim 1 , wherein, when the relaying device is added to a network, the relaying device control unit controls all ports of the relaying device to be inactive.

3. The network management apparatus according to claim 1 , further comprising: a withdrawal port searching unit that searches for, when the communication device belonging to the communication group is caused to withdraw from the communication group, the connection destination port of the communication device on the basis of the second storage unit, wherein the relaying device control unit further controls the connection destination port searched by the withdrawal port searching unit to disallow communication of the communication devices except for the communication device and the network management apparatus.

4. The network management apparatus according to claim 1 , wherein the ID is allocated for each of the communication devices whose information is stored in the first storage unit, the ID identifying the group to which the communication device belongs.

5. A network management method by which a network management apparatus manages a network including communication groups included in a same subnet, the network management method comprising: when a relaying device is added to the network, controlling all ports of the relaying device to be inactive; and on the basis of a first storage unit that stores therein the communication groups and information about communication devices belonging to the respective communication groups in association with each other and a second storage unit that stores therein a port of a communication device for each of the communication devices connected to the relaying device as a connection destination port, allowing the relaying device to be added to perform communication between the communication destination ports to allow communication with the communication devices belonging to the same communication group, and to disallow communication between the communication devices not belonging to the same communication group, the information about communication devices including a model name of each communication device and an ID that identifies each communication device, wherein when one or more of the communication device is caused to participate in the communication group, the network management method further comprises: searching for the connection destination ports controlling communication between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate; and controlling the connection destination ports searched at the searching to be active to allow communication only between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate when the model names of the communication devices caused to participate in the communication group can be acquired from the first storage unit.

6. The network management method according to claim 5 , wherein the ID is allocated for each of the communication devices whose information is stored in the first storage unit, the ID identifying the group to which the communication device belongs.

7. A non-transitory computer-readable recording medium having stored therein a program causing a computer to execute a process comprising: when a relaying device is added to a network including communication groups included in a same subnet, controlling all ports of the relaying device to be inactive; and on the basis of a first storage unit that stores therein the communication groups and information about communication devices belonging to the respective communication groups in association with each other and a second storage unit that stores therein a port of a communication device for each of the communication devices connected to the relaying device as a connection destination port, allowing the relaying device to be added to perform communication between the communication destination ports to allow communication with the communication devices belonging to the same communication group, and to disallow communication between the communication devices not belonging to the same communication group, the information about communication devices including a model name of each communication device and an ID that identifies each communication device, wherein when one or more of the communication device is caused to participate in the communication group, the process further comprises: searching for the connection destination ports controlling communication between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate; and controlling the connection destination ports searched at the searching to be active to allow communication only between the communication devices caused to participate and the communication device belonging to the same communication group as the communication devices caused to participate when the model names of the communication devices caused to participate in the communication group can be acquired from the first storage unit.

8. The non-transitory computer-readable recording medium according to claim 7 , wherein the ID is allocated for each of the communication devices whose information is stored in the first storage unit, the ID identifying the group to which the communication device belongs.